<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
 * Session Class
 *
 * This is extended from the default Session class in CodeIgniter 1.7.1.
 *
 * It fixes the serialization of Objects:
 * REF: http://codeigniter.com/forums/viewthread/95690/
 * BUG: http://codeigniter.com/bug_tracker/bug/7145/
 * BUG: http://codeigniter.com/bug_tracker/bug/5758/
 *
 * It makes session expiration handling better:
 * http://codeigniter.com/forums/viewthread/109645/
 *
 * It allows you to override the sess_persistent_cookie value for individual
 * sessions.
 *
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Sessions
 * @author		Ramesh Nair, HiddenTao Ltd
 * @link		http://www.hiddentao.com/
 */
class MY_Session extends CI_Session {

	var $sess_persistent_cookie	= FALSE;

	/**
	 * Session Constructor
	 *
	 * The constructor runs the session routines automatically
	 * whenever the class is instantiated.
	 */
	function MY_Session($params = array())
	{
		log_message('debug', "Session Class Initialized");

		// Set the super object to a local variable for use throughout the class
		$this->CI =& get_instance();

		// Set all the session preferences, which can either be set
		// manually via the $params array above or via the config file
		foreach (array('sess_encrypt_cookie', 'sess_use_database', 'sess_table_name', 'sess_expiration', 'sess_match_ip', 'sess_match_useragent', 'sess_cookie_name', 'cookie_path', 'cookie_domain', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key', 'sess_persistent_cookie') as $key)
		{
			$this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key);
		}

		// Load the string helper so we can use the strip_slashes() function
		$this->CI->load->helper('string');

		// Do we need encryption? If so, load the encryption class
		if ($this->sess_encrypt_cookie == TRUE)
		{
			$this->CI->load->library('encrypt');
		}

		// Are we using a database?  If so, load it
		if ($this->sess_use_database === TRUE AND $this->sess_table_name != '')
		{
			$this->CI->load->database();
		}

		// Set the "now" time.  Can either be GMT or server time, based on the
		// config prefs.  We use this to set the "last activity" time
		$this->now = $this->_get_time();

		// Set the session length. If the session expiration is
		// set to zero we'll set the expiration two years from now.
		if ($this->sess_expiration == 0)
		{
			$this->sess_expiration = (60*60*24*365*2);
		}

		// Set the cookie name
		$this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name;

		// Run the Session routine. If a session doesn't exist we'll
		// create a new one.  If it does, we'll update it.
		if ( ! $this->sess_read())
		{
			$this->sess_create();
		}
		else
		{
			$this->sess_update();
		}

		// Delete 'old' flashdata (from last request)
	   	$this->_flashdata_sweep();

		// Mark all new flashdata as old (data will be deleted before next request)
	   	$this->_flashdata_mark();

		// Delete expired sessions if necessary
		$this->_sess_gc();

		//log_message('debug', "Session routines successfully run");
	}

	/**
	 * Get Form Salt Key, use for security in form submit
	 * @return unknown_type
	 */
	function get_form_salt(){
		if ($this->userdata('_form_salt')){
			return $this->userdata('_form_salt');
		}else{
	        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
	        mt_srand(10000000*(double)microtime());
	        for ($i = 0, $str = '', $lc = strlen($chars)-1; $i < 16; $i++) {
	            $str .= $chars[mt_rand(0, $lc)];
	        }
	        $this->set_userdata('_form_salt', $str);
	        return $str;
		}
	}

	// --------------------------------------------------------------------

	/**
	 * Set whether the session should be persisted across browser sessions.
	 *
	 * This overrides the 'sess_persistent_cookie' config value for the current
	 * browser session.
	 *
	 * @access	public
	 *
	 * @param $value if TRUE then the session data will be persisted across
	 * browser sessions. If FALSE then it won't.
	 *
	 * @return	void
	 */
	function sess_persistent_cookie($value)
	{
		$this->userdata['persistent_cookie'] = $value;
		$this->sess_write();
	}





	// --------------------------------------------------------------------

	/**
	 * Write the session data
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_write()
	{
		// Are we saving custom data to the DB?  If not, all we do is update the cookie
		if ($this->sess_use_database === FALSE)
		{
			$this->_set_cookie();
			return;
		}

		// set the custom userdata, the session data we will set in a second
		$custom_userdata = $this->userdata;
		$cookie_userdata = array();

		// Before continuing, we need to determine if there is any custom data to deal with.
		// Let's determine this by removing the default indexes to see if there's anything left in the array
		// and set the session data while we're at it
		foreach (array('session_id','ip_address','user_agent','last_activity','persistent_cookie') as $val)
		{
			unset($custom_userdata[$val]);
			$cookie_userdata[$val] = $this->userdata[$val];
		}

		// Did we find any custom data?  If not, we turn the empty array into a string
		// since there's no reason to serialize and store an empty array in the DB
		if (count($custom_userdata) === 0)
		{
			$custom_userdata = '';
		}
		else
		{
			// Serialize the custom data array so we can store it
			$custom_userdata = $this->_serialize($custom_userdata);
		}

		// Run the update query
		$account_id = null;
		if (isset($this->userdata['account_id']) && $this->userdata['account_id']){
			$account_id = $this->userdata['account_id'];
		}
		$this->CI->db->where('session_id', $this->userdata['session_id']);
		$this->CI->db->update($this->sess_table_name, array('last_activity' => $this->userdata['last_activity'], 'account_id'=>$account_id, 'user_data' => $custom_userdata));

		// Write the cookie.  Notice that we manually pass the cookie data array to the
		// _set_cookie() function. Normally that function will store $this->userdata, but
		// in this case that array contains custom data, which we do not want in the cookie.
		$this->_set_cookie($cookie_userdata);
	}





	// --------------------------------------------------------------------

	/**
	 * Create a new session
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_create()
	{
		$sessid = '';
		while (strlen($sessid) < 32)
		{
			$sessid .= mt_rand(0, mt_getrandmax());
		}

		// To make the session ID even more secure we'll combine it with the user's IP
		$sessid .= $this->CI->input->ip_address();

		$this->userdata = array(
							'session_id' 	=> md5(uniqid($sessid, TRUE)),
							'ip_address' 	=> $this->CI->input->ip_address(),
							'user_agent' 	=> substr($this->CI->input->user_agent(), 0, 50),
							'last_activity'	=> $this->now,
							);


		// Save the data to the DB if needed
		if ($this->sess_use_database === TRUE)
		{
			$this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->userdata));
		}

		// add variables which weren't to be stored in the db
		$this->userdata['persistent_cookie'] = $this->sess_persistent_cookie;


		// Write the cookie
		$this->_set_cookie();
	}




	// --------------------------------------------------------------------

	/**
	 * Update an existing session
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_update()
	{
		// We only update the session every five minutes by default
		if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
		{
			return;
		}

		// Save the old session id so we know which record to
		// update in the database if we need it
		$old_sessid = $this->userdata['session_id'];
		$new_sessid = '';
		while (strlen($new_sessid) < 32)
		{
			$new_sessid .= mt_rand(0, mt_getrandmax());
		}

		// To make the session ID even more secure we'll combine it with the user's IP
		$new_sessid .= $this->CI->input->ip_address();

		// Turn it into a hash
		$new_sessid = md5(uniqid($new_sessid, TRUE));

		// Update the session data in the session data array
		$this->userdata['session_id'] = $new_sessid;
		$this->userdata['last_activity'] = $this->now;

		// _set_cookie() will handle this for us if we aren't using database sessions
		// by pushing all userdata to the cookie.
		$cookie_data = NULL;

		// Update the session ID and last_activity field in the DB if needed
		if ($this->sess_use_database === TRUE)
		{
			// set cookie explicitly to only have our session data
			$cookie_data = array();
			foreach (array('session_id','ip_address','user_agent','last_activity','persistent_cookie') as $val)
			{
				$cookie_data[$val] = $this->userdata[$val];
			}
			$account_id = null;
			if (isset($this->userdata['account_id'])){
				$account_id = $this->userdata['account_id'];
			}
			$this->CI->db->query($this->CI->db->update_string($this->sess_table_name, array('last_activity' => $this->now, 'session_id' => $new_sessid, 'account_id'=>$account_id), array('session_id' => $old_sessid)));
		}

		// Write the cookie
		$this->_set_cookie($cookie_data);
	}




	// --------------------------------------------------------------------

	/**
	 * Fetch the current session data if it exists
	 *
	 * @access	public
	 * @return	bool
	 */
	function sess_read()
	{
		// Fetch the cookie
		$session = $this->CI->input->cookie($this->sess_cookie_name);
		// No cookie?  Goodbye cruel world!...
		if ($session === FALSE)
		{
			//log_message('debug', 'A session cookie was not found.');
			return FALSE;
		}

		// Decrypt the cookie data
		if ($this->sess_encrypt_cookie == TRUE)
		{
			$session = $this->CI->encrypt->decode_cookie($session);
		}
		else
		{
			// encryption was not used, so we need to check the md5 hash
			$hash	 = substr($session, strlen($session)-32); // get last 32 chars
			$session = substr($session, 0, strlen($session)-32);

			// Does the md5 hash match?  This is to prevent manipulation of session data in userspace
			if ($hash !==  md5($session.$this->encryption_key))
			{
				log_message('error', 'The session cookie data did not match what was expected. This could be a possible hacking attempt.');
				$this->sess_destroy();
				return FALSE;
			}
		}

		// Unserialize the session array
		$session = $this->_unserialize($session);
		// Is the session data we unserialized an array with the correct format?
		if ( ! is_array($session) OR
			!isset($session['session_id']) OR
			!isset($session['ip_address']) OR
			!isset($session['user_agent']) OR
			!isset($session['last_activity']) OR
			!isset($session['persistent_cookie'])
			)
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Is the session current?
		if (($session['last_activity'] + $this->sess_expiration) < $this->now)
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Does the IP Match?
		if ($this->sess_match_ip == TRUE AND $session['ip_address'] != $this->CI->input->ip_address())
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Does the User Agent Match?
		if ($this->sess_match_useragent == TRUE AND trim($session['user_agent']) != trim(substr($this->CI->input->user_agent(), 0, 50)))
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Is there a corresponding session in the DB?
		if ($this->sess_use_database === TRUE)
		{
			$this->CI->db->where('session_id', $session['session_id']);

			if ($this->sess_match_ip == TRUE)
			{
				$this->CI->db->where('ip_address', $session['ip_address']);
			}

			if ($this->sess_match_useragent == TRUE)
			{
				$this->CI->db->where('user_agent', $session['user_agent']);
			}

			$query = $this->CI->db->get($this->sess_table_name);


			// No result?  Kill it!
			if ($query->num_rows() == 0)
			{
				$this->sess_destroy();
				return FALSE;
			}

			// Is there custom data?  If so, add it to the main session array
			$row = $query->row();
			if (isset($row->user_data) AND $row->user_data != '')
			{
				$custom_data = $this->_unserialize($row->user_data);
				if (is_array($custom_data))
				{
					foreach ($custom_data as $key => $val)
					{
						$session[$key] = $val;
					}
				}
			}
		}

		// Session is valid!
		$this->userdata = $session;
		unset($session);

		return TRUE;
	}




	// --------------------------------------------------------------------

	/**
	 * Write the session cookie
	 *
	 * @access	public
	 * @return	void
	 */
	function _set_cookie($cookie_data = NULL)
	{
		if (is_null($cookie_data))
		{
			$cookie_data = $this->userdata;
		}

		// Persistent cookie?
		if (!$cookie_data['persistent_cookie'])
		{
			$expiration = 0;
		}
		else
		{
			$expiration = $this->sess_expiration + time();
		}

		// Serialize the userdata for the cookie
		$cookie_data = $this->_serialize($cookie_data);

		if ($this->sess_encrypt_cookie == TRUE)
		{
			$cookie_data = $this->CI->encrypt->encode_cookie($cookie_data);
		}
		else
		{
			// if encryption is not used, we provide an md5 hash to prevent userside tampering
			$cookie_data = $cookie_data.md5($cookie_data.$this->encryption_key);
		}

		// Set the cookie
		//setcookie(
//					$this->sess_cookie_name,
//					$cookie_data,
//					$expiration,
//					$this->cookie_path,
//					$this->cookie_domain,
//					0
//				);
        //DangLD: cookie hết hạn khi người dùng đóng trình duyệt
        setcookie(
                    $this->sess_cookie_name,
                    $cookie_data,
                    0,
                    $this->cookie_path,
                    $this->cookie_domain,
                    0
                );
	}



	// --------------------------------------------------------------------


	/**
	 * Serialize an array
	 *
	 * This function first converts any slashes found in the array to a temporary
	 * marker, so when it gets unserialized the slashes will be preserved
	 *
	 * @access	private
	 * @param	array
	 * @return	string
	 */
	function _serialize($data)
	{
		if (is_array($data))
		{
			foreach ($data as $key => $val)
			{
				if (!is_object($val))
					$data[$key] = str_replace('\\', '{{slash}}', $val);
			}
		}
		else
		{
			if (!is_object($data))
				$data = str_replace('\\', '{{slash}}', $data);
		}

		//return serialize($data);
		return addslashes(json_encode($data));
	}

	// --------------------------------------------------------------------

	/**
	 * Unserialize
	 *
	 * This function unserializes a data string, then converts any
	 * temporary slash markers back to actual slashes
	 *
	 * @access	private
	 * @param	array
	 * @return	string
	 */
	function _unserialize($data)
	{
		//$data = @unserialize(strip_slashes($data));
		$data = @json_decode(strip_slashes($data), true);

		if (is_array($data))
		{
			foreach ($data as $key => $val)
			{
				if (!is_object($val))
					$data[$key] = str_replace('{{slash}}', '\\', $val);
			}

			return $data;
		}

		if (!is_object($data))
			return str_replace('{{slash}}', '\\', $data);
		else
			return $data;
	}
	/**
	 * set session for payment
	 * @param $session_key
	 * @param $data
	 */
	function set_session_payment($session_key,$data){
		$this->CI->load->model('payment_session_m');
		//$user_data = $this->_serialize($data);
		$data['user_data'] = $this->_serialize($data);
		$data['session_key'] = $session_key;
		if(!$this->CI->payment_session_m->checkSessionExists($session_key)){
			$this->CI->payment_session_m->add($data);
		}else{
			$params['session_key'] = $session_key;
			$this->CI->payment_session_m->updateByParams($params,$data);
		}
	}
	/**
	 * get session from table payment_session with time timeout =30
	 * @param unknown_type $session_key
	 */
	function get_session_payment($session_key){
		$this->CI->load->model('payment_session_m');
		$sessions =$this->CI->payment_session_m->getDataBySessionKey($session_key);
		if($sessions)
			$session = $this->_unserialize($sessions->user_data);
		else
			return NULL;
		return $session;
	}
}
// END Session Class


/* End of file */